1. Field
This invention relates to theater lighting systems and provides an improved cross connect panel for such systems.
2. State of the Art
A variety of cordless electric cross connect panels are in use for theater lighting systems. These panels are sometimes referred to within the art as "patch panels," and include a multiplicity of bus bars running substantially parallel to each other and connected to either the power supply or load side of a theater lighting circuit. Cross connect devices of some types are mounted transverse the bus bars and are themselves connected to either the load or power supply side of the circuit opposite the side connected to the bus bars. The cross connect devices are adapted to selectively interconnect a load with a power supply, often in association with circuit breaker means.
Cross connect panels which have gained acceptance commercially are disclosed and claimed in U.S. Pat. Nos. 2,796,473; Re 24,586; 3,467,922; 3,496,421; 3,603,747; and Re 28,134. Although the devices illustrated by these patents have enjoyed considerable commercial success, they nevertheless retain certain limitations and disadvantages from both mechanical and operational standpoints. For example, it is desirable for a cross connect panel to have the capability of expansion both in the number of power supplies and in the number of load circuits which can be accommodated. The panels of the prior art are limited in this respect. Moreover, inordinate care must be taken in operating many of the devices of the prior art because they are incapable of "breaking" a circuit without relocating the cross connect device to a special, reserved "off" transverse position with respect to the bus bars. Expanding the capacity of prior art patch panels by incorporating additional cross connect devices involves skilled disassembly and assembly techniques and sacrifices the structural integrity of the system. The cross connect panels currently in use also return the problem--common to switching apparatus--of concentrated arcing and the attendent difficulties of erosion of point contacts.
The foregoing are illustrative only of the problems associated with cross connect panels of the prior art. In general, it may be stated that a great many structural and electrical inconveniences are accepted by the industry because of the usefulness of cross connect systems as compared to alternative approaches to theater lighting and the absence of more acceptable alternatives.